Police officials in Dhaka suspect an arson attack and said they were searching for the perpetrators.

At least four people were killed and others injured in Bangladesh after a passenger train caught fire in a suspected arson attack, police officials said.

Friday’s incident adds to a tense atmosphere in the country ahead of Sunday’s incident Choosewhich the opposition wants to boycott and disrupt with a general strike.

Fire service official Rakjibul Hasan said that at around 9pm (1500 GMT), at least four buses on the Benapole Express, which arrived in the capital Dhaka from the western city of Jessore, caught fire. The fire quickly spread through the train.

Residents initially tried to extinguish the fire before seven fire engines joined the effort, said Khandaker al-Moin of the police’s rapid response battalion unit at the scene. It took almost two hours to put out the fire, he said.

Dhaka Metropolitan Police deputy chief Mohid Uddin described the incident as a planned act of sabotage to create panic among citizens ahead of the elections.

“We will definitely find out the perpetrators involved in such heinous attacks,” Uddin said.

Police chief Anwar Hossain also told the AFP news agency: “We suspect that the fire incident was an act of sabotage,” without giving further details.

An unnamed rescuer told private broadcaster Somoy TV that hundreds had rushed to pull people out of the burning train.

“We saved many. But the fire spread quickly,” he said. According to Somoy TV, some Indian citizens were also traveling on the train.

Bangladesh has experienced frequent violence surrounding elections, and Sunday’s vote comes amid an increasingly polarized political culture led by two powerful women – current Prime Minister Sheikh Hasina and former Prime Minister Khaleda Zia, an opposition leader currently under House arrest is in place.

After Hasina refused to accept Zia’s Bangladesh National Party (BNP)’s demands for a neutral caretaker government to conduct the elections, the BNP has decided to boycott the elections.

Meanwhile, at least three people have been killed in violence stemming from political clashes since the election campaign officially began on December 18.

The campaign officially ended on Friday morning, but there is widespread speculation that this vote – which Hasina could win for the fourth consecutive time and fifth time in office overall – is being rigged.

The international community has expressed concern about the way the vote went.

Charles Whiteley, the European Union ambassador to the country, said in a letter to Bangladesh’s electoral commission that the bloc would not send a full team of observers because “it is not sufficiently clear whether the necessary conditions are being met.”

The UN Secretary-General’s deputy spokeswoman, Florencia Soto Nino, said in New York on Wednesday: “We are closely monitoring the process and hope that all elections will take place in a transparent and organized manner.”

On Thursday, at a major campaign rally in Fatullah near Dhaka, Hasina urged everyone to maintain peace.

The Electoral Commission has announced that elections will be held in 299 out of 300 constituencies across the country on Sunday.